Thursday, August 24, 2006

Warning: Geekiness Ahead

Is there a way out of the stem cell debate? Robert Lanza hopes so.

A research team headed by Lanza has hatched a new method for producing stem cells that does not involve the destruction of human embryos. Normally, the creation of a stem cell line - a colony of living stem cells with the potential to become human tissue - involves destroying a relatively mature embryo and extracting the stem cells. Lanza instead removes one cell from a younger embryo and induces it to form a stem-cell line. This allows the embryo to continue to grow normally. Nature's Helen Pearson reports (link may not be accessible outside NCSU) that the cell lines have lasted for eight months and have formed different kinds of human tissue.

Of course, the viability of the method has yet to be proven. As Rick Weiss reports (link above), the conditions of the experiment involve contaminants that might make the organs produced unusable. And as Pearson reports, the experimentalists only got two stem-cell lines out of 16 in-vitro fertilization (IVF) embryos. This is horribly inefficient, and the extraction techniques will have to improve if this method is to compete with the current method in the scientists' minds.

Furthermore, no one is sure whether extracting a cell from an embryo at that stage is harmful to the development of the embryo. Lanza claims that the process is actually fairly common in current IVF practice, but he also says that he wants to improve efficiency by taking more than one cell out of the embryo. At that point, it is uncertain what would happen to the embryo's development.

You would think this would satisfy those concerned with the destruction of embryos for therapeutic purposes, right? Not so fast. Some believe that a cell taken from an embryo can itself become an embryo under the right conditions, and so using such a cell would still constitute the destruction of human life. This is a somewhat silly objection; there is no real evidence that this development could occur, and it almost certainly could not occur without some sort of outside encouragement. It is similar to saying that women should not ovulate because their eggs could become human embryos "under the right conditions." And even if it were possible, allowing it to occur would constitute human cloning, which is already taboo. Those who raise this objection are probably just grasping at straws.

A more serious objection is the one raised by the Bush administration in response to the research. According to Weiss, the White House responded to the research with a statement that "any use of human embryos for research purposes raises serious ethical concerns" and that he would just as soon see stem cells developed "without the need for human embryos." This is a legitimate objection, but one that is still on shaky ground from a logical standpoint. Humans give up their cells for scientific research or for other purposes on a regular basis. Babies give up blood cells for disease analysis. Even fetuses often give up some of their genetic material to scientific analysis - this process, known as amniocentesis, is a relatively common part of modern pregnancy. If the embryo's development is not harmed by the cell extraction, as Lanza claims, then how is using an extracted cell for scientific purposes any more unethical than any other use of a person's cells? And if the Bush administration is correct and life begins at conception, why is it any less ethical to take a cell from a person thirty hours after fertilization than it is to take a cell from a person thirty years after conception?

More science news:

- In a rare triumph of science over small-minded politics, the FDA approved the sale of the emergency contraceptive pill over-the-counter to women over 18. There is some grumbling that the pill isn't available to everyone, but the effect of the hormone boost to younger women is uncertain, and so women under 18 will not be able to purchase the pill. Fair enough. However, there was absolutely no scientific reason for restricting the sale of the emergency contraceptive to adult women. The reasons given for the holdup are frivolous at best; the accusation that the pill causes an "early abortion" by preventing a fertilized egg from implanting in the uterus ignores the fact that fertilized eggs often fail to implant in the uterus naturally, and accusing "the pill" of increasing promiscuity is akin to blaming Kevlar vests for gun violence. The whole difficulty of the process highlights how deeply flawed the FDA approval process is, and how it needs to be simplified, made more transparent, and limited to considering scientific objections.

- Pluto has been voted off the galactic island. Apparently, its orbit is too dependent upon Neptune (whose orbital path it crosses; in fact, until recently, Pluto was nearer the sun than Neptune). However, all is not lost for everyone's favorite iceball: it will now be considered a "dwarf planet." Which means it will be renamed "Sneezy." The asteroid Ceres will be a dwarf planet as well. Perhaps it will be "Happy." And I'm all for renaming the cumbersomely named 2003 UB313 "Dopey."

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